ina = input()
inb = input()

l = int(ina)
cw1 = inb.count("W")
cw2 = inb[-cw1:].count("W")
print(cw1-cw2) ina = input() ina input() input inb = input() inb input() input l = int(ina) l int(ina) int ina cw1 = inb.count("W") cw1 inb.count("W") inb.count inb count "W" cw2 = inb[-cw1:].count("W") cw2 inb[-cw1:].count("W") [-cw1:].count [-cw1:] inb -cw1: -cw1 cw1 count "W" print(cw1-cw2) print cw1-cw2 cw1 cw2 cw1 = inb.count("W") inb.count("W") cw1 inb = input() input() inb l = int(ina) int(ina) l cw2 = inb[-cw1:].count("W") inb[-cw1:].count("W") cw2 ina = input() input() ina
ina = input()
inb = input()

l = int(ina)
cw1 = inb.count("W")
cw2 = inb[-cw1:].count("W")
print(cw1-cw2)